Continuing declines in genital warts in young women and heterosexual men: population effects of the national quadrivalent HPV vaccination in Australia, 2004-2010

From mid-2007 Australia funded a universal free vaccination program for all females between 12 and 26 years, but not for men or for women who were older than 26 years. Vaccine coverage rates of ~80% were achieved for school-girls, though coverage was probably lower for young women in the community. To determine the population effect of the vaccine program we established a national surveillance network to measure trends in clinical presentations for genital warts. Eight sexual health services dispersed around Australia provided data on all new patients between 2004 and 2010, including new diagnoses of genital warts, demographics, sexual behaviour, and HPV vaccination status (Lancet Inf Dis 2011;11:39).

Among 134,939 new patients we identified 11,194 new cases of genital warts. Before the vaccination program there was no change in the proportion of women or heterosexual men diagnosed with genital warts. To the end of 2010 we detected a 73% decline in the proportion of young resident women diagnosed with genital warts that was ongoing (p-trend <0.0001). In contrast, a 25% decline in young non-resident women only approached significance (p-trend=0.06), and we could not detect any significant decline in genital warts among older women or men who have sex with men. Interestingly, the proportion of resident heterosexual men diagnosed with genital warts declined by 35% (p-trend <0.0001), particularly among younger men (44%). By 2010, 65% of resident women of free vaccine-eligible age reported prior HPV vaccination, approaching 80% in the youngest women.
The vaccination program is having a major impact on the incidence of genital warts in young Australian women, with some protection of heterosexual men resulting from herd immunity. These declines seem to be ongoing as the most highly vaccinated cohort that was vaccinated at school approaches its peak period for exposure to HPV.

Statement of Competing Interests Funded by CSL Biotherapies. All data held and analysed by the Kirby Institute with no input from funding source.

Dr Basil Donovan

Basil is a practicing Sexual Health Physician and head of the Sexual Health Program at the Kirby Institute, University of New South Wales. His research and policy interests include clinical and public health aspects of HIV/AIDS and other STIs and STI prevention strategies, in various populations of public health importance.